x86, boot: stylistic cleanups for boot/compressed/head_64.S (b40d68d5) · Commits · 戴 / test

arch/x86/boot/compressed/head_64.S

+31 −21

Original line number	Diff line number	Diff line
		@@ -37,8 +37,10 @@
		.code32
		ENTRY(startup_32)
		cld
		/* test KEEP_SEGMENTS flag to see if the bootloader is asking
		* us to not reload segments */
		/*
		* Test KEEP_SEGMENTS flag to see if the bootloader is asking
		* us to not reload segments
		*/
		testb $(1<<6), BP_loadflags(%esi)
		jnz 1f

		@@ -49,7 +51,8 @@ ENTRY(startup_32)
		movl %eax, %ss
		1:

		/* Calculate the delta between where we were compiled to run
		/*
		* Calculate the delta between where we were compiled to run
		* at and where we were actually loaded at. This can only be done
		* with a short local call on x86. Nothing else will tell us what
		* address we are running at. The reserved chunk of the real-mode
		@@ -70,10 +73,11 @@ ENTRY(startup_32)
		testl %eax, %eax
		jnz no_longmode

		/* Compute the delta between where we were compiled to run at
		/*
		* Compute the delta between where we were compiled to run at
		* and where the code will actually run at.
		*/
		/* %ebp contains the address we are loaded at by the boot loader and %ebx
		*
		* %ebp contains the address we are loaded at by the boot loader and %ebx
		* contains the address where we should move the kernel image temporarily
		* for safe in-place decompression.
		*/
		@@ -155,7 +159,8 @@ ENTRY(startup_32)
		btsl $_EFER_LME, %eax
		wrmsr

		/* Setup for the jump to 64bit mode
		/*
		* Setup for the jump to 64bit mode
		*
		* When the jump is performend we will be in long mode but
		* in 32bit compatibility mode with EFER.LME = 1, CS.L = 0, CS.D = 1
		@@ -184,7 +189,8 @@ no_longmode:

		#include "../../kernel/verify_cpu_64.S"

		/* Be careful here startup_64 needs to be at a predictable
		/*
		* Be careful here startup_64 needs to be at a predictable
		* address so I can export it in an ELF header. Bootloaders
		* should look at the ELF header to find this address, as
		* it may change in the future.
		@@ -192,7 +198,8 @@ no_longmode:
		.code64
		.org 0x200
		ENTRY(startup_64)
		/* We come here either from startup_32 or directly from a
		/*
		* We come here either from startup_32 or directly from a
		* 64bit bootloader. If we come here from a bootloader we depend on
		* an identity mapped page table being provied that maps our
		* entire text+data+bss and hopefully all of memory.
		@@ -209,7 +216,8 @@ ENTRY(startup_64)
		movl $0x20, %eax
		ltr %ax

		/* Compute the decompressed kernel start address. It is where
		/*
		* Compute the decompressed kernel start address. It is where
		* we were loaded at aligned to a 2M boundary. %rbp contains the
		* decompressed kernel start address.
		*
		@@ -241,7 +249,8 @@ ENTRY(startup_64)
		addq $(32768 + 18 + 4095), %rbx
		andq $~4095, %rbx

		/* Copy the compressed kernel to the end of our buffer
		/*
		* Copy the compressed kernel to the end of our buffer
		* where decompression in place becomes safe.
		*/
		leaq _end_before_pgt(%rip), %r8
		@@ -260,7 +269,7 @@ ENTRY(startup_64)
		leaq relocated(%rbx), %rax
		jmp *%rax

		.section ".text"
		.text
		relocated:

		/*
		@@ -271,8 +280,7 @@ relocated:
		leaq _end_before_pgt(%rbx), %rcx
		subq %rdi, %rcx
		cld
		rep
		stosb
		rep stosb

		/* Setup the stack */
		leaq boot_stack_end(%rip), %rsp
		@@ -311,8 +319,10 @@ gdt:
		.quad 0x0000000000000000 /* TS continued */
		gdt_end:

		/*
		* Stack and heap for uncompression
		*/
		.bss
		/* Stack and heap for uncompression */
		.balign 4
		boot_heap:
		.fill BOOT_HEAP_SIZE, 1, 0

Admin message